Pulp screen



Feb. 4, 1941. H, w D wN PULP SCREEN Filed Feb. 23, 1939 3 Shasta-Sheet l Aman Attorney Feb. 4, 1941.

H. W, DOWNS PULP SCREEN Filed Feb.A 25. 1939 3 Sheets-Shut 2 I uINI.

NVENTQR Qf/enry Downs Feb. 4, 1941.v H, w, DQwNs 2,230,321

` A rum scnznu Filed Feb. 23-. 1939 y3 Shouts-Shot 3 wan-ron; I Henry Downs A *1 9 r TAAL mmxl Patented Feb. 4, 1941 uru'i'laz'ov STATES f y. 2,230,321'L PULrsonEEN j Henry William Downs, Lennoicrville, Quebec,

f Canada .imitation February 2s, 1939, serial No. 258,065 v 1 claim. (ci. sia- 30) This invention relates to improvements in aA pulp screen plate fastener. Its primary object being to devise and construct means to secure pulp screen plates in the screening vats. Said means being adaptable for `rapid changing of the screens thereby reducing-the loss of time required for this purpose to a minimum.

A further object of the invention is to provide a screen plate fastening device havingmeans to prevent leakage of the pulp material around the sides.

Another object of the invention is to .provide a screen plate fastener adaptable to screen plates of reduced thickness. Said screen plates being 5 more efficient to allow the pulp materialto flow through more freely. The fastener as herein constructed will prevent vibration of the screen plates thereby permitting use of the thin screen plates made from high grade metals at low cost. i.. W

With these and other objects in View that may appear while the descriptionproceeds the invention resides in the novel construction and arrangement of parts as hereinafter more specically set forth, claimed and shown in the accompanying drawings forming part of this application and in which: i

Fig. l'ls a plan viewof a vathaving the screens secured therein by my improved screen plate fas- 80 tenen Fig. 2 is a side view of the same.

Fig. 3 is an end view of the open end.

Fig. 4 is an end View of the closed end.

v Fig. 5 is an enlarged sectional view showing 35 details of the fastener.

Fig. 6 is a sectional view atright angles to that shown in Fig. 5. y y

Referring more in detail to the drawings wherein similar reference characters designate corre- 40 sponding parts throughout the several views it" will be seen the invention comprises a support or Vvat frame Ill preferably of wood on which screen frames Il are secured by bolts l2 and. washers I3. Said screen frames are adapted to be joined together to accommodate any number of screen plates as each frame normally accommodates four screen plates.

The frame joint is shown in detail in Fig. 5, wherein -it will be seen the ends Il are bolted to- 50 gether by bolts l5 and a. key I6 is provided to engage keyways I1 in each end'member to ensure l correct alignment and to prevent any movement. It will be seen the frame has a number of transverse bars I3 in each of which is a longitudinal u slot I3 wherein the downwardly turned ends 20,

fagainstV the end of the 'screen plate.

of the screens 2|- are placed and a ,small strip 'of felt 22 or similar material placed in the bottom thereof.

In the drawings a vat is shown` having an open vend and a closed end. In the former a 4i plate 23 is screwed to the frame ID and bears The key 16 engages a key-way I1 and a corresponding key-way in the said frame I0.

The closed end construction is provided with lo the sealing or tightening which consists of a sealing strip 24 which extends the width of the vat. Said sealing strip has a lower bearing edge 25 having alongitudinal slot 26 for felt or similar packing material. This vbearing edge engages 15 the screen plates 2| and clamps them against the screen frame Il. The strip is arranged to accommodate a locking nut 21 behind the face 23 and a. locking bolt 29 threadably engages the same. Saidbolt is constructed with a collar 30 20 whichV bears on the top edge of the sealing strip while the `bolt passes through an aperture 3| provided therefor. The nut 21 has a lip 32 which engages a slot 33 in a locking plate 33a. Said locking plate is positioned vertically between the 25 screen frame l0; and sealing -strip 24, and the support frame I0, and `is, secured to'th'e'latterY by screws 34. On the lowerendof the .locking v plate is .avr right angled projection 35which enf gages the key-way I1 of the frame |.Il and -an- 30 chors the plate thereto. In this manner it will be seen that as the vbolt is turned the pressure is applied below and above the screens thereby preventing any leakage of the pulp material past 1 the-joint. f 35 SideA sealing strips 36 are-provided and are f constructed similarly to the end strip. The locking bolt, nut and plate are similar and operatel in the same manner as the end sealing device and therefore need not bdescribedjin detail. 40

From the `foregoing description it will be seen that the disclosure is not 'limited in any way to number'or size onscreenv plates or to the detailed construction of the same providing the ends are designed to .fit the screen frames. It 5 will also be apparent that the screens may be readily removed by loosening the device as the sealing strips 'may be detached entirely when the junction with the accompanying drawings .without further detailed description.

While the preferred embodiment of the invention has been disclosed it is understood that minor changes in the details of construction. combination and arrangement of cooperating elements may be resorted to within the scope of what is claimed without departing from the spirit of the inYention. n t v Y. v Q il Iclairnlin .l

A pulp screen comprising `a. vat frame, screen plate frames adapted to `be secured together end to end, means securing the same to the vat frame, key-ways formed transversely in the adjoining facesjof the 'frame and a key engaging said keyways where two frames are joined, screen plates having turned down edges forming anges, chan-v nel bars v extending transversely' o! the screen plate frames adaptedv to receive the @angesct adjacent 'screen plates inV -meeting lrelation.' a

packing strip in the bottom of said channels bridging the joint between the flanges of the screen plates, sealing strips arranged to engage the upper surface of the screen plates, said sealing strips having a lower bearing surface arranged to bear on the upper surface of the ends of the screen plates, a lockingplate positioned between the sealing strip, screen plate frame,

andthe vattvframe to vwhich itfis isecured, said 7 Vlocking platehaving ajtransverse projection on the lower end engagingthe transverse key-way in the screen plate frame, a locking nut having a projecting lip thereon, said lip engaging an aperture in the locking` plate to bear upward d on the same, a bolt having a collar below the nut thereof and lug arranged to bear on the sealing strip as theidevice is tightened, substanvvtially as set forth.y

HENRY WILLIAM DOWNS.l 20v 

